• # LGM Pharma is a Clemastine Fumarate CAS# 14976-57-9 API supplier distributor based in the USA. Inquire about DMF, cGMP, price, availability, samples, sourcing, purity and more.
  • # Questions? Call our customer API support number 1-(800)-881-8210.
  • # LGM Pharma offers this active ingredient but not the finished dosage forms.
  • Inquire about this product >>

Product Details:

  • Product Name: Clemastine Fumarate
  • CAS #: 14976-57-9
  • Mode of Action:

    Clemastine is a selective histamine H1 antagonist and binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine.

  • Pharmacodynamics:

    Clemastine is an antihistamine with anticholinergic (drying) and sedative side effects. Antihistamines competitively antagonize various physiological effects of histamine including increased capillary permeability and dilatation, the formation of edema, the "flare" and "itch" response, and gastrointestinal and respiratory smooth muscle constriction. Within the vascular tree, H1- receptor antagonists inhibit both the vasoconstrictor and vasodilator effects of histamine. Depending on the dose, H1- receptor antagonists can produce CNS stimulation or depression. Most antihistamines exhibit central and/or peripheral anticholinergic activity. Antihistamines act by competitively blocking H1- receptor sites. Antihistamines do not pharmacologically antagonize or chemically inactivate histamine, nor do they prevent the release of histamine.

  • Metabolism:
    Antihistamines appear to be metabolized in the liver chiefly via mono- and didemethylation and glucuronide conjugation.
  • Toxicity:

    Oral LD50 in rat and mouse is 3550 mg/kg and 730 mg/kg, respectively. Antihistamine overdosage reactions may vary from central nervous system depression to stimulation. In children, stimulation predominates initially in a syndrome which may include excitement, hallucinations, ataxia, incoordination, muscle twitching, athetosis, hyperthermia, cyanosis convulsions, tremors, and hyperreflexia followed by postictal depression and cardio-respiratory arrest. Convulsions in children may be preceded by mild depression. Dry mouth, fixed dilated pupils, flushing of the face, and fever are common. In adults, CNS depression, ranging from drowsiness to coma, is more common.

  • IUPAC: (R-(R*, R*))-2-(2-(1-(p-Chlorophenyl)-1-phenylethoxy)ethyl)- 1-methylpyrrolidinium hydrogen fumarate
  • Formula: C21-H26-Cl-N-O.C4-H4-O4
  • Synonyms: (+)-(2R)-2-(2-(((R)-p-Chloro-alpha-methyl-alpha-phenylbenzyl)oxy)ethyl)-1-methylpyrrolidine fumarate (1:1), (+)-2-(2-((p-Chloro-alpha-methyl-alpha-phenylbenzyl)oxy)ethyl)-1-methyl pyrrolidine fumarate, Agasten, Aloginan, Alphamin, Anhistan, Clemanil, Clemastine fumarate, Clemastine hydrogen fumarate, EINECS 239-055-2, Fuluminol, HSDB 6507, Inbestan, Kinotomin, Lacretin, Lecasol, Maikohis, Mallermin-F, Marsthine, Masletine, Meclastine hydrogen fumarate, Mecloprodine, Piloral, Pyrrolidine, 2-(2-(1-(4-chlorophenyl)-1-phenylethoxy)ethyl)-1-methyl-, (R-(R*,R*))-, (E)-2-butenedioate (1:1), Reconin, Tavegil, Tavegyl, Tavist, Tavist-1, Telgin-G, Topcare dayhist allergy, Trabest, UNII-19259EGQ3D, Xolamin
  • SMILES: c1([C@@](c2ccccc2)(OCC[C@@H]2[N@@](CCC2)C)C)ccc(Cl)cc1.C(=CC(O)=O)C(O)=O
  • InChl: InChI=1S/C21H26ClNO.C4H4O4/c1-21(17-7-4-3-5-8-17,18-10-12-19(22)13-11-18)24-16-14-20-9-6-15-23(20)2;5-3(6)1-2-4(7)8/h3-5,7-8,10-13,20H,6,9,14-16H2,1-2H3;1-2H,(H,5,6)(H,7,8)/b;2-1+/t20-,21-;/m1./s1
  • General Reference:


    1. Hayashi H, Okajima M, Yamada K: Atrial T (Ta) loop in dogs with or without atrial injury. Am Heart J. 1976 May;91(5):607-17. Pubmed
    2. Schran HF, Petryk L, Chang CT, O’Connor R, Gelbert MB: The pharmacokinetics and bioavailability of clemastine and phenylpropanolamine in single-component and combination formulations. J Clin Pharmacol. 1996 Oct;36(10):911-22. Pubmed
Products currently covered by valid US Patents are offered for R&D use in accordance with 35 USC 271(e)+A13(1). Any patent infringement and resulting liability is solely at buyer risk.

API’s From Quality Manufacturers:

  • Streamlined API supply towards initial research stages as well as larger quantities of cGMP material for clinical trials and product commercialization
  • Premium quality GMP certified and fully accredited API manufacturing plants


  • Technical packages as well as access to filed DMF,
    ASMF or CEP (subject to availability)
  • Regulatory and technical assistance towards any
    submission type based on specific customer requirements

LGM Pharma Acquires CDMO

On July 27, 2020, LGM Pharma announced its acquisition of the formulation development and drug product contract manufacturing business of Nexgen Pharma, Inc. As a result, you will notice our new logo and visuals throughout the website. We’re working on updates to reflect the exciting, expanded CDMO capabilities and services we now can offer you.

This website uses cookies. By using our site, you agree to our terms of service